CN111656803B

CN111656803B - Virtual test environment for active noise management systems

Info

Publication number: CN111656803B
Application number: CN201880080759.1A
Authority: CN
Inventors: 蔡霆力; D.S.温卡塔; D.特朗普; A.库马尔
Original assignee: Harman International Industries Inc
Current assignee: Harman International Industries Inc
Priority date: 2017-12-20
Filing date: 2018-12-20
Publication date: 2022-08-19
Anticipated expiration: 2038-12-20
Also published as: US20200342846A1; US11308932B2; JP2021507570A; JP2023169348A; CN111656803A; WO2019123345A1; EP3729833A1

Abstract

A system for evaluating a noise management module of a vehicle includes a controller programmed to filter speaker signals from the noise management module using an audibility model to produce an audibility sound signal to create a spatial effect to simulate sound in the vehicle at a predetermined location within the vehicle that is different from a location corresponding to a microphone used by the noise management module.

Description

Virtual test environment for active noise management system

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional application serial No. 62/608,275 filed on 12/20/2017, the disclosure of which is hereby incorporated by reference in its entirety.

Technical Field

The present application relates generally to a hardware-in-the-loop (HIL) system for a vehicle active noise management system.

Background

Many efforts have been made to create a quiet cabin environment in a vehicle. One typical goal of vehicle design is to minimize audible noise in the passenger compartment. Consumers desire isolation from road noise, driveline noise, and other unwanted noise sources. Vehicles may include various insulating materials between the passenger compartment and the noise-producing components. However, the insulating material may be expensive and increase the weight of the vehicle. Some modern vehicles include active noise management systems to reduce audible noise in the passenger compartment.

Active noise management systems may operate by using microphones and speakers in an attempt to cancel unwanted noise. The active noise management system may detect the noise signal via a microphone. The microphone signal may be processed and a speaker output signal may be generated that cancels out the noise. For example, the speaker may generate a cancellation signal 180 degrees out of phase with the unwanted noise signal at the microphone location. The effect is to create cancellation noise that cancels the unwanted noise.

The development of active noise management systems requires extensive testing in the actual vehicle environment. Tuning and calibration requires trial and error in order to arrive at an effective calibration set for the system. During vehicle development, it may be difficult to obtain vehicle time because there are many systems that compete for vehicle time in development. Once a vehicle is obtained, vehicle and environmental conditions may affect the testing process. For example, wind, weather, air temperature, component temperature, and road conditions may vary from test to test. Therefore, sufficient replication testing may require additional testing time and effort.

Disclosure of Invention

A hardware-in-the-loop (HIL) system for interfacing with an active noise management system includes a controller configured to output a microphone signal to the active noise management system. The controller is also configured to receive a speaker signal from the active noise management system. The controller is further configured to process the speaker signal through a transfer function that models the acoustic response from the speaker to the microphone. The controller is configured to generate a microphone signal based on the speaker signal and the noise signal. The controller is also configured to render the spatial sound field using the binaural information (e.g., adding an audible effect). HIL systems may be configured to use audibility to evaluate the sound field within the cabin.

A system for evaluating a noise management module of a vehicle, the system comprising a controller programmed to receive a speaker signal from the noise management module and transmit a microphone signal to the noise management module. The controller is also programmed to filter the speaker signal using the vehicle acoustic model to generate a sound signal caused by the speaker signal at a location in the vehicle corresponding to a location of a microphone associated with the noise management module. The controller is further programmed to combine the sound profile (profile) with the sound signal to generate a microphone signal. The controller is further programmed to filter the speaker signal using the audibility model to produce a rendered sound signal to create a spatial listening impression to simulate sound caused by the speaker signal at a predetermined location within the vehicle different from a location corresponding to the location of the microphone.

The predetermined position may be associated with a seating position within the vehicle and an expected positioning of a head of a vehicle occupant seated in the seating position. The audible model may be derived from actual speaker data from the vehicle and actual microphone data from an evaluation microphone placed near a predetermined location in the vehicle. The controller may also be programmed to combine the rendered sound signal with a sound profile to generate an evaluation sound signal. The controller may also be programmed to output the evaluation sound signal to an audio output device. The audible model may represent the acoustic environment of the vehicle and may define a transfer function between the sound caused by the speaker signal and the sound at the predetermined location. The vehicle acoustic model may be derived from previously recorded speaker data from the vehicle and previously recorded data from microphones in the vehicle associated with the noise management module. The sound profile may include sound signals previously recorded in the vehicle. The sound profile may include synthesized sound data. The controller may also be programmed to transmit bus communication data and sensor signals corresponding to and synchronized with the sound profile to the noise management module.

A method for simulating performance of a noise management module of a vehicle and implemented in a controller includes receiving speaker signals from the noise management module and generating a sound profile. The method also includes outputting the sound signal to a microphone input of a noise management module based on the sound profile and a cabin acoustic model that defines a cabin acoustic transfer function between the speaker signal and a microphone located in the vehicle and associated with the noise management module. The method further includes outputting the audio signal to an audio output device based on the sound profile and an audibility model defining an audibility transfer function between the speaker signal and a differently positioned location within the vehicle corresponding to a microphone of the noise management module for rendering the sound to create a spatial listening impression to recreate the sound impression at the location.

The sound profile may include sound signals previously recorded in the vehicle. The method may further include outputting the bus data and the sensor signal associated with the sound profile to a noise management module. The method may further comprise generating an audible model from actual speaker data from the vehicle and data from an evaluation microphone placed in the vicinity of the location. The position may be associated with a seating position within a vehicle and an expected positioning of a head of a vehicle occupant seated in the seating position.

A computer program product embodied in a non-transitory computer readable medium programmed for simulating performance of a noise management module of a vehicle, comprising instructions for: receiving a speaker signal from a noise management module, transmitting a microphone signal to the noise management module, and generating a sound profile. The computer program product further includes instructions to output a microphone signal via a microphone interface based on the sound profile and a cabin acoustic model defining a cabin acoustic transfer function between the speaker signal and a microphone located in the vehicle and associated with the noise management module. The computer program product further includes instructions to output an audio signal to an audio output device based on the sound profile and an audibility model defining an audibility transfer function between the loudspeaker signal and a location within the vehicle different from the location corresponding to the microphone for creating a spatial listening impression to recreate the sound impression at the location.

The computer program product also includes instructions for exchanging data associated with the sound profile and the sensor signal between the controller and the noise management module. The position may be associated with a seating position within a vehicle and an expected positioning of a head of a vehicle occupant seated in the seating position. The cabin acoustic model may be derived from actual speaker data from the vehicle and actual data from microphones in the vehicle associated with the noise management module, and the audible model may be derived from actual speaker data and actual microphone data from evaluation microphones placed near said location in the vehicle. The audio output device may be a headset.

Drawings

FIG. 1 depicts an active noise management system within a vehicle environment.

Fig. 2 depicts an active noise management system and a test environment including a hardware-in-the-loop (HIL) system with an evaluation module.

FIG. 3 depicts a possible flow chart for collecting vehicle data.

Fig. 4 depicts a possible flow diagram for operating an active noise management HIL system.

Detailed Description

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Embodiments of the present disclosure generally provide a plurality of circuits or other electrical devices. All references to circuits and other electrical devices and the functions they provide are not intended to be limited to inclusion of only what is illustrated and described herein. Although particular tags may be assigned to the various circuits or other electrical devices disclosed, such tags are not intended to limit the operating range of the circuits and other electrical devices. Such circuits and other electrical devices may be combined with and/or separated from each other in any manner based on the particular type of electrical implementation desired. It should be appreciated that any circuit or other electrical device disclosed herein may include any number of microprocessors, integrated circuits, Field Programmable Gate Arrays (FPGAs), memory devices (e.g., flash memory, Random Access Memory (RAM), Read Only Memory (ROM), Electrically Programmable Read Only Memory (EPROM), Electrically Erasable Programmable Read Only Memory (EEPROM), or other suitable variations thereof), and software that cooperate with each other to perform the operations disclosed herein. Additionally, any one or more of the electrical devices may be configured to execute a computer program embodied in a non-transitory computer readable medium programmed to perform any number of the functions as disclosed herein.

Testing and calibration of a vehicle active noise management system may be improved by implementing an active Noise Management System (NMS) hardware-in-the-loop (HIL) test system. The NMS-HIL system can be configured to allow insertion and operation of noise management modules in a virtual environment. The NMS-HIL may be configured to simulate a vehicle noise environment and provide signals to the noise management module under test. The test results may be monitored and analyzed. The audible features can be used to subjectively and objectively evaluate the results virtually.

Fig. 1 depicts a vehicle 100 that includes a Noise Management Module (NMM) 102. The NMM 102 may be coupled to various inputs and outputs. The NMM 102 may include a microprocessor and volatile memory for executing instructions and programs. The NMM 102 may include volatile memory for storing programs and data. Volatile memory may include any memory configured to retain data between power cycles. The NMM 102 can include one or more connectors 106 configured to receive a mating connection from the vehicle side. The NMM 102 may implement various features related to vehicle noise management. For example, the NMM 102 may implement engine noise cancellation and road noise cancellation algorithms. The NMM 102 may also implement electronic sound synthesis to generate desired noise within the cabin.

The vehicle 100 may include one or more microphones 108 electrically coupled to the NMM 102 via the connector 106. The connector 106 is depicted as a single connector, but may be one or more connectors depending on the vehicle configuration. The microphone 108 may be located at various locations within the vehicle 100. The placement of the microphone 108 may be configured to best represent audible signals at locations where a vehicle occupant may be seated. The microphone 108 may be integrated with various components of the vehicle cabin (e.g., headliner, door trim). The microphone 108 may provide an analog signal representative of audible noise at the location. In some configurations, the microphone 108 may convert the signal to a digital signal and pass the signal in digital form.

The vehicle 100 may include one or more speakers 104 electrically coupled to the NMM 102 via an electrical connector 106. The speaker 104 may be part of an audio entertainment system. One or more of the speakers 104 may be separate from the audio entertainment system. The NMM 102 may include an amplifier to drive the speaker 104 to a desired level. The speaker 104 may have an associated impedance. Speakers 104 may be positioned in various portions of vehicle 100. For example, speakers 104 may be mounted in various locations, including doors, instrument panels, headliners, seats, rear hatches, and side panels. Some speakers may be placed in the headliner near each seating location, above the seat headrest or each seat.

The NMM 102 can interface with a vehicle network 112. The vehicle network may be a digital communication link between the NMM 102 and other control modules within the vehicle 100. The vehicle network 112 may be a Controller Area Network (CAN) bus, a Local Interconnect Network (LIN) bus, a Media Oriented System Transfer (MOST) bus, an ethernet and/or a FlexRay bus. The vehicle network 112 may also include a proprietary bus architecture. The vehicle network 112 may facilitate data communication between the NMM 102 and other modules within the vehicle 100. For example, various signals (such as engine speed, accelerator pedal position, brake pedal position, engine torque, vehicle speed, and transmission gear selector position) may be transmitted over the vehicle network 112. A signal indicative of a powertrain operating mode (e.g., economy or reduced cylinder operating mode) may be received over the vehicle network 112. The NMM 102 may operate noise management functions using signals received from the vehicle network 112. The NMM 102 can also provide signals on the vehicle network 112.

The NMM 102 can interface with various inputs 114. For example, the input 114 may include any signal wired directly to the NMM 102 via the connector 106. For example, the inputs 114 can include switch inputs for enabling and disabling operation of the NMM 102. Input 114 may include engine speed. Input 114 may include signals from one or more accelerometers. The input 114 may also include additional audio signals (e.g., for music compensation purposes). The input 114 may be a reference signal. The set of inputs 114 may depend on the vehicle configuration. The input 114 may include any discrete and/or analog input. The NMM 102 can include associated interface circuitry and software drivers for converting the input 114 into digital form for use by the microprocessor-based system.

The NMM 102 can interface with various outputs 116 wired directly to the NMM 102 via the connector 106. For example, the output 116 may include a status light to indicate the status of the NMM 102. The output 116 may include trigger signals intended for other modules. The trigger signal may be intended to trigger a specific function in the receiving module. In other examples, the buffered speed signal may be transmitted through the output 116. The set of outputs 116 may depend on the vehicle configuration. Output 116 may include any discrete and/or analog output. The NMM 102 may include associated interface circuitry and software drivers.

The NMM 102 can interface with a power supply 118 via the connector 106. Power and ground signals from the power supply system 118 may be routed through the connector 106. The power source 118 may be a low voltage bus powered by a battery and an alternator. For example, a typical automotive application may operate on a 12 volt power supply. The NMM 102 can receive power from a power supply 118.

During operation of the vehicle 100, the NMM 102 may process inputs from the microphone 108 to generate signals that are output to the speaker 104. The process may utilize other information from the vehicle network 112. For example, at higher engine loads and/or at higher vehicle speeds, noise typically increases. The NMM 102 can utilize the vehicle speed signal to adjust the speaker output volume to compensate for the expected increase in noise level. The NMM 102 may implement a noise cancellation algorithm to reduce unwanted noise heard by occupants of the vehicle 100. The NMM 102 may implement various other control strategies.

The NMM 102 may be developed and calibrated by testing the system in the vehicle 100. Proper calibration may require repeated test and calibration cycles under uniform conditions. However, replicating a uniform condition in the vehicle 100 may require additional testing time and effort. For example, a calibration process may specify operations to be performed at a fixed speed on a specified road surface. In other examples, a test requiring a particular velocity and/or acceleration profile may require several iterations to reproduce accurately and consistently. Accordingly, there is a need for improved methods for developing and testing such systems.

To facilitate development and testing and evaluation of active noise management systems, a simulator may be used. The simulator may allow for the development and testing of active noise management systems on a laboratory bench in a laboratory environment. In this way, the simulator may result in improved repeatability of the test conditions. In addition, less vehicle time is required, which minimizes the need for actual test vehicles. The simulator may be configured to use actual data acquired from the vehicle 100. The simulator may also be configured to simulate various vehicle conditions using predefined test scripts to facilitate virtual and subjective assessment of the sound field within the cabin.

A vehicle Data Acquisition System (DAS)150 may be installed in the vehicle 100 to collect various data and signals. In some configurations, the functions performed by the vehicle DAS 150 may be implemented in the NMM 102. For example, the NMM 102 may include selectable operating modes for vehicle data collection. During this data collection mode, the normal noise management features may be disabled. During operation of the vehicle DAS 150, the NMM 102 may be disabled or removed from the vehicle 100. Vehicle DAS 150 may be configured to receive input from microphone 108 and vehicle network 112. The vehicle DAS 150 may also be configured to receive signals from other inputs 114. Calibration or testing procedures for the NMM 102 may be specified and performed while the vehicle DAS 150 is operating. Vehicle DAS 150 may be configured to collect and store signals sampled during the testing process. The result may be a database of input values that the NMM 102 would expect to receive during various vehicle operating conditions.

Vehicle DAS 150 can include a microprocessor and volatile memory for executing instructions and programs. Vehicle DAS 150 can include volatile memory for storing programs and data. Volatile memory may include any memory configured to retain data between power cycles. Volatile memory may include flash memory, hard drives, and USB drives. The volatile memory may be configured to be removable to facilitate the transfer of data. Vehicle DAS 150 may include a user interface that allows a user to control and monitor the operation of vehicle DAS 150. The communication via the user interface may be a wired (e.g., USB, ethernet) and/or wireless connection (e.g., IEEE 802.11, bluetooth). Vehicle DAS 150 may include an interface for connecting to vehicle network 112.

Vehicle DAS 150 may be used to collect noise and vehicle data for later playback. For example, the microphone signal may be periodically sampled along with data from the vehicle network 112. The data may be sampled at periodic intervals and stored in non-volatile memory for later use. Data may be stored with timestamps to identify the relative timing of the samples so that accurate playback may be achieved. Vehicle DAS 150 may be configured to collect uncompensated data from the vehicle. That is, data can be collected without the NMM 102 modifying the operation of the sound within the cabin. The vehicle DAS 150 may collect vehicle noise data including engine noise during various speed and acceleration profiles. Test scenarios for collecting data may be developed to emphasize particular noise sources. For example, different test scenarios and conditions may be envisaged for recording engine noise, wind noise, suspension noise and road noise. The test scenario may be configured such that one type of noise is dominant in order to isolate a particular noise source.

Vehicle DAS 150 may be configured with a connector compatible with connector 106. In this configuration, the vehicle DAS 150 may be plugged into the vehicle 100 instead of the NMM 102. In this configuration, no change in any vehicle wiring is required. In some configurations, the functions performed by the vehicle DAS 150 may be implemented in the NMM 102. The NMM 102 can include a data acquisition mode that can be entered through a diagnostic command or other trigger.

The vehicle DAS 150 may also be configured to capture signals used to generate a cabin acoustic model. Vehicle DAS 150 may be electrically coupled to speakers 104. Vehicle DAS 150 may be configured to output signals to speakers 104 and record inputs from microphones 108. For some tests, vehicle DAS 150 may drive only one of the speakers 104 at a time. The loudspeaker signals may be configured to facilitate characterization of a cabin acoustic model. That is, the microphone's response to sound provided by the speaker 104. The speaker output signal may be at a predetermined frequency and a predetermined amplitude. For example, vehicle DAS 150 may output a series of sinusoidal waveforms to speaker 104. The frequency and amplitude of the waveform may vary. By sweeping through a range of audible frequencies, the cabin environment can be characterized. The microphone signal may be sampled at a suitable sampling rate to capture the dynamic content of the sound wave (e.g., at least twice the highest expected frequency).

Vehicle DAS 150 may include one or more evaluation microphones 152. The evaluation microphone 152 may be used to collect binaural sound information from inside the vehicle cabin for audibility purposes. Signals from the evaluation microphone 152 may be recorded by the vehicle DAS 150 to gather binaural information from the vehicle cabin separate from the vehicle microphone signals. For this reason, additional wiring connections may be required between the evaluation microphone 152 and the vehicle DAS 150. The evaluation microphone 152 may be used to capture measurements of Head Related Transfer Functions (HRTFs) in each seat of the cabin. The evaluation microphone 152 may be placed in the vehicle at a position where the head of the occupant may be normally located. The position of the evaluation microphone 152 may be a predetermined position. The predetermined position may be defined by coordinates such as a three-dimensional distance from one of the speakers 104 or one of the microphones 108. As previously described, vehicle DAS 150 may be configured to output predetermined signals to speakers 104 and record inputs received from evaluation microphone 152. The data may be used to characterize the acoustic response in the vicinity of the occupant.

The loudspeaker output signal may be a combination of waveforms configured to excite the dynamics of the intended transfer function sufficiently to allow accurate identification. The speaker output signal may be configured with sufficient frequency and amplitude content to properly excite the system dynamics. The corresponding responses of the microphone 108 and the evaluation microphone 152 may be recorded. The collected data may be stored in a non-volatile memory for later processing.

A cabin or vehicle acoustic model may be generated from data collected by vehicle DAS 150. The transfer functions from each speaker output to each microphone input can be developed resulting in a set of transfer functions. The offline processing unit may be configured to process the microphone and speaker data to generate a transfer function representing the acoustic model of the vehicle cabin. Various techniques may be used to derive the transfer function from the input and output of the system. For example, a model structure may be selected, and then microphone and speaker data may be processed using a system identification method to define parameters of the model structure. For example, a least squares estimation algorithm may be used to estimate the parameters. In other examples, deconvolution techniques based on convolution in the time domain may be used with exponential sinusoidally scanned loudspeaker output signals.

The vehicle acoustic model may be expressed in the frequency domain. The microphone and speaker data may be processed using discrete fourier transforms. The microphone and speaker data may be converted to the frequency domain using a discrete fourier transform. The parameters of the frequency domain transfer function may be calculated from the frequency domain microphone and speaker data. An estimation algorithm may be performed to generate frequency domain parameters of the transfer function. The time-domain transfer function may be derived by calculating an inverse fourier transform of the frequency-domain transfer function. In other configurations, the frequency domain transfer function may be derived by computing a fourier transform of the time domain transfer function.

HRTFs may also be expressed in the frequency domain. The microphone and speaker data may be evaluated using a discrete fourier transform process. The evaluation microphone and speaker data may be converted to the frequency domain using a discrete fourier transform. The parameters of the frequency domain transfer function can be calculated from the frequency domain estimated microphone and loudspeaker data. An estimation algorithm may be performed to generate frequency domain parameters of the HRTF. The time-domain transfer function may be derived by calculating an inverse fourier transform of the frequency-domain transfer function. In other configurations, the frequency domain transfer function may be derived by computing a fourier transform of the time domain transfer function.

Fig. 2 depicts the NMM 102 coupled to a hardware-in-the-loop (HIL) system 200 for simulating a vehicle environment. The HIL system 200 can be configured to provide signals to the NMM 102 such that the NMM 102 functions as it would in the vehicle 100. Additionally, the HIL system 200 accepts outputs from the NMM 102 in the same manner as the vehicle 100. The HIL system 200 allows the NMM 102 to operate as if it were in the vehicle 100. The HIL system 200 can be configured to receive signals from the NMM 102 and provide signals to the NMM 102 to simulate the auditory environment of the car. The simulation may utilize a transfer function derived from actual vehicle data as previously described herein. In this manner, the HIL system 200 can provide an accurate simulation of the vehicle environment for testing and calibrating the NMM 102. The HIL system 200 may also provide a virtual environment that adds the ability to be used to subjectively and objectively assess the audibility of the sound field within the vehicle.

Audibility is a technique that renders a sound field through a playback device, such as a headphone or speaker array, to create a spatial effect. This technique is used to create an external sound image for the listener, reconstructing the soundscape into a 3D impression. Audibility may require special handling during both recording and playback.

During recording, microphones (e.g., evaluation microphone 152) may be placed directly on both ears of the listener (or phantom) (binaural recording) or placed around the head of the listener (or phantom) in a particular pattern (e.g., a circle) to capture the interaction of the head and torso of the listener (or phantom) with the sound field at the time of the sound event. For example, during data collection, the evaluation microphone 152 may be positioned at a location where the head of the occupant is expected to be. Data collection may include moving the evaluation microphone 152 to a different location. For example, the seat position may be adjusted to various positions to change the relative positioning of the evaluation microphone 152 with respect to the speaker 104.

During playback, the binaural recording may be played back to the same listener through calibrated headphones or binaural speakers. Personal Head Related Transfer Functions (HRTFs) of different listeners may be used to compensate for head and torso differences and then convolved with the source signal to get the rendered audible effect.

The effect of the audibility is to produce a sound field that is heard by a person in a particular seating location within the vehicle. That is, the sound may sound like emanating from different directions. The audibility may provide this effect by producing sound through a set of headphones or a binaural speaker. Users of the virtual environment may place headphones over their ears to receive sound. The HIL system 200 may be configured to simulate the response of various seating positions within the vehicle. The seating position may be selectable by an operator.

The HIL system 200 may include a microprocessor and volatile memory for executing instructions and programs. The HIL system 200 can include volatile memory for storing programs and data. Volatile memory may include any memory configured to retain data between power cycles. Volatile memory may include flash memory, hard drives, and USB drives. The volatile memory may be configured to be removable to facilitate data transfer to other computing platforms. The modules depicted in the HIL system 200 may be implemented as hardware, software, or some combination thereof.

The HIL system 200 can include a HIL connector 206 compatible with the NMM connector 106. If the NMM connector 106 is comprised of multiple connectors, the HIL connector 206 can also be comprised of multiple compatible connectors. The HIL connector 206 can be plugged into the NMM connector 106. The NMM connector 106 plugs into the HIL connector 206 as it does with the vehicle 100.

The HIL system 200 may include an NMM interface 216. The NMM interface 216 can include circuitry to provide compatible signals to the NMM 102. Additionally, the NMM interface 216 may include hardware and software features configured to transmit signals between the NMM 102 and the HIL system 200. The NMM interface 216 can be configured to provide a specified impedance for each connection. The NMM interface 216 can be configured to selectively couple and decouple power or ground connections to the NMM 102 to test the NMM 102's response to a connection loss or power-on condition. The selective coupling and decoupling may be under control of a microprocessor. In some configurations, selective coupling and decoupling may be performed manually using switches.

The NMM interface 216 may be configured to provide microphone data to the NMM 102 via the microphone interface 212. The microphone interface 212 may include one or more digital-to-analog converters (DACs) configured to convert digital signals to analog signals. Additionally, the microphone interface 212 may be configured to output an analog signal representative of a microphone signal of the vehicle microphone 108. The response of the microphone interface 212 may be configured to match the parameters of the vehicle microphone 108. For example, the microphone interface 212 may have a similar impedance as the vehicle microphone 108. In this way, the NMM 102 may not be able to identify any differences between the signals provided by the microphone interface 212 and the actual vehicle microphone 108. The microphone interface 212 may emulate the dynamic response of a microphone and may include hardware or software filters to achieve the results.

The NMM interface 216 may include a vehicle network interface 210, the vehicle network interface 210 configured to transmit data to vehicle network terminals of the NMM 102. The vehicle network interface 210 may include hardware and software drivers to communicate with the NMM 102 through vehicle network terminals. The HIL system 200 can also include a vehicle network manager 218 configured to provide vehicle network signals used by the NMM 102. The vehicle network manager 218 may include a combination of hardware and software drivers. The vehicle network manager 218 may generate signals and messages for transmission to the NMM 102 through the vehicle network interface 210. The vehicle network manager 218 may also convert signals and messages transmitted by the NMM 102 for use within the HIL system 200. The vehicle network manager 218 may provide sufficient signals and messages to simulate the vehicle environment without error. The vehicle network manager 218 may be configured to selectively alter messages or signal data to simulate various conditions in the vehicle 100. For example, the vehicle network manager may be configured to alter the signal to simulate an error condition in the vehicle module to test the NMM 102 response to the error condition.

The NMM interface 216 may include the NMM output interface 208. The NMM output interface 208 can be configured to provide signals output from the NMM 102 to the HIL system 200. The NMM output interface 208 may include hardware and software drivers to provide signals to the HIL system 200. For example, the analog signal output from the NMM 102 can be filtered and converted to a digital signal.

The NMM interface 216 may include the NMM input interface 204. The NMM input interface 204 may be configured to provide signals from the HIL system 200 to the NMM 102. The NMM input interface 204 may include hardware and software drivers to provide signals to the NMM 102. For example, the NMM input interface 204 may convert digital signals generated by the HIL system 200 into analog signals compatible with the input specification of the NMM 102. The NMM input interface 204 may be configured to provide a reference signal and an input to the NMM 102. For example, any analog signal (e.g., an engine speed signal) that may be used by the NMM 102 may be provided via the NMM input interface 204. For example, in a road noise cancellation application, the NMM 102 may receive the accelerometer signal as an analog input. The NMM input interface 204 may be configured to output the accelerometer signals in a format acceptable to the NMM 102.

The NMM interface 216 may include a power management interface 214. The power management interface 214 may be configured to provide power and ground signals to the NMM 102. The power management interface 214 may be controlled by the HIL system 200 to facilitate power cycling of the NMM 102. The power management interface 214 may be configured to provide voltage and current to the NMM 102. The HIL system 200 may be configured to selectively control the voltage and current output from the power management interface 214. For example, the HIL system 200 may be capable of varying voltage levels to test the response of the NMM 102 to various power supply voltage levels.

The NMM interface 216 may include a speaker interface 202 to provide speaker data to the HIL system 200. The speaker interface 202 may include hardware and software drivers for converting speaker signals output by the NMM 102 into signals that may be processed by the HIL system 200. For example, the speaker interface may include one or more analog-to-digital converters (ADCs) configured to convert analog speaker signals to digital values. The speaker interface may include circuitry to provide compatible circuitry for the NMM 102. For example, the impedance of the speaker interface 202 may be selectable to emulate a variety of speakers. For example, the speaker interface 202 may be configurable to selectively provide an impedance of 4 ohms, 8 ohms, or 16 ohms to simulate the electrical characteristics of the speaker.

The components of the NMM interface 216 can be configured to be easily changed or updated. For example, the components of the NMM interface 216 may be implemented on a separate plug-in circuit board to allow for changes in functionality when changing designs. In some configurations, the components of the NMM interface 216 may include software modules that can be easily inserted and removed. Such features may enable the HIL system 200 to be quickly updated for different vehicle configurations.

The HIL system 200 may include an input-output (I/O) management module 220. The I/O management module 220 may be configured to generate signals for transmission between the NMM 102 and the HIL system 200. The I/O management module 220 can interface with the NMM output interface 208 to provide signals to the NMM 102. The I/O management module 220 can interface with the NMM input interface 204 to receive signals from the NMM 102.

The HIL system 200 may include a playback module 222. The playback module 222 can be configured to output previously recorded vehicle data, which can include data from the vehicle microphone 108 and the evaluation microphone 152, and generate signals within the HIL system 200 to check the NMM 102 for response to the previously recorded data set. The playback module 222 may also receive input from the vehicle network manager 218. Signals from the vehicle network manager 218 may be used to select playback parameters and characteristics to properly simulate the corresponding vehicle or environmental conditions. For example, the previously recorded data may include microphone and vehicle network data from a vehicle test cycle. The playback module 222 can extract signals from previously recorded data and output the signals to the NMM 102 and HIL system 200. The playback module 222 may output signals at the same timing as the recording data. The playback module 222 can include the ability to play back any recorded microphone data or output of the NMM 102 at the HIL 200 to represent the vehicle sound field at the ear location. For example, the playback module 222 may output a microphone signal recorded during a vehicle test period. The microphone data may be transmitted to the NMM 102. The NMM 102 can process the microphone data and generate speaker outputs in response. The playback module 222 may include a first output 242, the first output 242 being a signal from the vehicle microphone 108. The playback module 222 may include a second output 244, the second output 244 being the signal from the evaluation microphone 152. The playback module 222 can interface with the I/O management module 220 to transmit analog and/or digital signals to the NMM 102. The playback module 222 can be configured to transmit previously recorded analog signals (e.g., accelerometer signals) to the NMM 102. The analog signal and the sound signal may be output at the same timing as the original recording.

The playback module 222 may also be configured to include playback of the synthesized data. The custom playback data may be generated manually offline, or may be generated through simulation. An off-line simulation may be performed to generate noise data for various scenarios to be tested. The composite data may be useful in situations where vehicle data is difficult to obtain. For example, the synthesized data may be used to generate a scenario requiring a limit vehicle speed. The playback module 222 may also be configured to provide a combination of vehicle data and synthetic data. For example, to simulate noise conditions that are not captured in the vehicle data, additional noise signals may be added to the data.

The playback module 222 may also be configured to provide additional sound. For example, the playback module 222 may include the ability to play music similar to a vehicle stereo system. The playback module 222 may include the ability to play announcements from various vehicle systems. For example, the playback module 222 can incorporate sound output from a navigation system. This capability allows the HIL system 200 to test the response of the NMM 102 to typical vehicle sounds to ensure that such sounds do not degrade. The playback module 222 may include a library of such vehicle sounds that may be played in various combinations to simulate system operation.

The HIL system 200 may implement a vehicle acoustic model 224. The vehicle acoustic model 224 may be implemented as a program or application. The vehicle acoustic model 224 may utilize a cabin acoustic model determined offline. The vehicle acoustic model 224 may be expressed in the frequency domain or the time domain. The parameters of the vehicle acoustic model 224 may be derived from actual vehicle test data. The vehicle acoustic model 224 may be in the form of one or more transfer functions or impulse responses. The vehicle acoustic model 224 may receive speaker data and/or signals via the speaker interface 202. The vehicle acoustic model 224 may process the speaker signals using transfer functions to generate microphone signals. The microphone signal may be a sound signal expected at the location of the vehicle microphone 108 within the vehicle cabin. The vehicle acoustic model 224 may also receive input from the I/O management module 220. The vehicle acoustic model 224 may also receive input from the vehicle network manager 218. For example, the window status signal may be provided by the vehicle network manager 218. Signals from the vehicle network manager 218 may be used to select acoustic models and/or parameters to properly simulate vehicle or environmental conditions.

The vehicle acoustic model 224 may output a time domain signal representing the sound signal expected at each vehicle microphone 108. The transfer function may be expressed as a time domain function (e.g., impulse response). The vehicle acoustic model 224 may implement one or more convolution functions to process the speaker input signal. Convolving the time-domain transfer function with the loudspeaker input signal may provide a time-domain signal indicative of the sound at the associated microphone location. The vehicle acoustic model 224 may also be implemented as one or more filters or frequency domain transfer functions. The parameters of the filter or frequency domain transfer function may be converted to a corresponding discrete time transfer function to process the sampled loudspeaker signal. The vehicle acoustic model 224 may be implemented and/or include features that minimize any delay in the signal due to computing latency.

The vehicle acoustic model 224 can output a signal indicative of the sound at the location of each microphone caused by the speaker output generated by the NMM 102. The signal may be combined or combined with the sound signal (e.g., first output 242) generated by the playback module 222. The outputs of the vehicle acoustic model 224 and the playback module 222 may be routed to a combiner 226. The combiner 226 may be an adder configured to add the signals together. For example, the playback module 222 provides a sound signal at the microphone 108 that represents the actual noise during vehicle testing. The vehicle acoustic model 224 provides a sound signal at the microphone 108 that represents the sound generated by the NMM 102 to cancel out the noise. The two signals may be combined to represent the resulting sound signal at the microphone, including the playback signal and the compensation signal. The output of the combiner 226 may be provided to the microphone interface 212 for transmission to the NMM 102.

The HIL system 200 can also include an audible model 248. The evaluation microphone 152 may be used to derive transfer function data or impulse response data, which may also be referred to as binaural information, at the location of the passenger's ear in each seat. The audible model 248 may output a time domain signal that represents the sound signal expected at the ear of an occupant at a given location in the vehicle. The transfer function may be expressed as a time domain function (e.g., impulse response). The audible model 248 may implement a convolution function to process the signal from the speaker input signal. Convolving the time-domain transfer function with the loudspeaker input signal may provide a time-domain signal indicative of the sound at the ear of the occupant. The convolution process includes the cabin acoustic characteristics derived from the head related transfer function and recorded by the evaluation microphone 152. The audible model 248 may also be implemented as a filter or a frequency domain transfer function. The parameters of the filter or frequency domain transfer function may be converted to a discrete time transfer function to process the sampled loudspeaker output signal. The audible model 248 may be implemented and/or include features to minimize any delay in the signal due to computational latency.

The audible model 248 may output a signal indicative of the sound at the location of each evaluation microphone 152 caused by the speaker output generated by the NMM 102. The signal may be combined or combined with the sound signal (e.g., second output 244) generated by the playback module 222. The outputs of the audibility model 248 and the playback module 222 can be routed to the second combiner 246. The second combiner 246 may be an adder configured to add the signals together. For example, the playback module 222 provides a sound signal at the evaluation microphone 152 that represents the actual noise during vehicle testing. The audible model 248 provides a sound signal at the evaluation microphone 152 that represents the sound generated by the NMM 102 to cancel out the noise. The two signals may be combined to represent the resulting sound signal at the evaluation microphone 152, including the playback signal and the compensation signal. The output of the combiner 246 may be provided to the evaluation module 228 and may be output to the headphones 234 and/or the binaural speaker 236.

In this manner, the HIL system 200 simulates the interior of the vehicle and allows for testing and calibration of the NMM 102. The HIL system 200 simulates the response of the vehicle sound system to control signals provided by the NMM 102. The HIL system 200 may also include an evaluation module 228. The evaluation module 228 may process the raw vehicle microphone signal provided by the playback module 222 and the compensation sound provided by the combiner 226. The evaluation module 228 may process the original evaluation microphone signal provided by the playback module 222 and the compensation sound provided by the combiner 246. The evaluation module 228 may be programmed to automate the analysis of the signal. For example, the evaluation module 228 may provide statistics regarding the noise reduction level. The output of the evaluation module 228 may be saved and stored in non-volatile memory for later comparison. The evaluation module 228 may allow for comparison of different control strategies implemented by the NMM 102. Additionally, the evaluation module 228 can enable comparison of the NMM 102 parameter changes. The evaluation module 228 may also record and analyze the signals provided by the vehicle network manager 218, the NMM input interface 204, and the NMM output interface 208. The evaluation module 228 can also examine the frequency spectrum of the playback signal and the compensation signal to evaluate the effectiveness of the system. For example, the evaluation module 228 may perform a fourier transform on the signal to generate frequency content.

The HIL system 200 can also be configured to test the noise synthesis capability of the NMM 102. The NMM 102 may include an electronic sound synthesis algorithm. For example, the NMM 102 may be configured to generate simulated engine noise during an acceleration event. The evaluation module 228 may be configured to evaluate noise generated by the electronic sound synthesis system. The playback module 222 can include simulation data for testing the noise generation capabilities of the NMM 102. For example, the NMM 102 may be configured to generate an engine noise sound profile during certain acceleration events. The playback module 222 may be configured with various acceleration events. A test may be performed using the acceleration event to determine if a correct response was obtained.

The HIL system 200 may be configured with an external interface module 232. External interface module 232 may be configured to interface with external computing system 230. The external interface module 232 may include a Universal Serial Bus (USB), ethernet, and/or wireless network interface. The external interface module 232 may allow the external computing system 230 to access the HIL system 200. For example, external computing system 230 may be used to monitor HIL system 200 and update parameters of HIL system 200. The external computing system 230 may transmit the configuration data to the HIL system 200 via the external interface module 232. In addition, the HIL system 200 may be reprogrammed via the external interface module 232. For example, the external computing system 230 may be configured to reprogram the vehicle acoustic model and the audibility model and modify the parameters of the models. External interface module 232 may allow HIL system 200 to report data to external computing system 230. The external interface module 232 may also allow the operation of the HIL system 200 to be controlled and monitored by the external computing device 230.

The external interface module 232 may be configured to interface with other devices. The external interface module 232 may include an interface for a headset 234, which headset 234 may be connected to the HIL system 200. The headphones 234 may provide a stereo output to the listener. The external interface module 232 may also include an interface for one or more speakers 236. For example, a binaural speaker may be connected to the HIL system 200. The binaural speaker system may comprise a left speaker and a right speaker and be configured to minimize crosstalk between the left source and the right source. The external interface module 232 may also be configured to include an interface for a Virtual Reality (VR) system 238. For example, the VR system 238 may include audio and visual feedback to the simulated user. The external interface module 232 may also include an interface to a driving simulator 240. The driving simulator 240 may allow a user to simulate various driving conditions. For example, the driving simulator 240 may be used to provide velocity and acceleration profiles to the HIL system 200.

The external computing system 230 may be configured to provide input to the playback module 222. For example, an operator of the external computing system 230 may select a test to be performed or request playback of a predetermined test pattern.

The HIL system 200 may also include a display for interfacing with an operator. The display may be a touch screen display. In addition, the HIL system 200 may include an input device, such as a keyboard or mouse, to allow input from an operator. The HIL system 200 may include hardware and software drivers for providing an operator interface.

The HIL system 200 may utilize an audible method to render a sound field at the ear locations of each seat in the vehicle cabin. The HIL system 200 may include a set of headphones 234 or binaural speakers 236 to enable virtual subjective assessment of the interior sound quality of the vehicle cabin. The HIL system 200 can be extended to provide feedback on the output of the headset 234 with a head tracking device inserted to provide a complete representation of the sound field within the vehicle in each seat as the head moves. The operator may select various sound signals to play through the headset 234. For example, the operator may choose to listen to the raw vehicle microphone data and the compensated microphone data. The operator may also choose to listen to the raw evaluation microphone data or the compensated evaluation microphone data with the audibility model applied.

FIG. 3 depicts a possible flow chart for generating noise curves and vehicle data. At operation 302, vehicle operation data may be recorded. For example, the vehicle may be operated at various speed and acceleration profiles. The signals at each microphone 108 and evaluation microphone 152 may be sampled and stored in a vehicle data database 308 for later use. Additionally, information from the vehicle network 112 may be recorded. The vehicle operation data may be periodically sampled and stored with the time stamp data. The recording may be triggered manually by an operator. The recording may also be automated based on the operating conditions of the vehicle.

At operation 304, the vehicle audio system may be operated to provide data for modeling the vehicle acoustic and audible environment. For example, a predetermined speaker output signal may be generated and played through speaker 104. Signals generated by the microphone 108 and the evaluation microphone 152 in response to the speaker output may be recorded and stored in the vehicle database 308 for later processing.

At an operation 306, a vehicle acoustic model may be developed from the data stored from operation 304. The speaker and microphone data may be used to construct one or more transfer functions between the speaker 104 and the microphone 108. The transfer function may define the response of the microphone 108 to the output of the speaker 104. The parameters describing the transfer function may be saved in the vehicle acoustic model database 310 for later use. The parameters may be communicated to the HIL system 200.

At operation 312, an audibility model may be developed from the data stored from operation 304. The speaker and evaluation microphone data may be used to construct one or more audible transfer functions between the speaker 104 and the evaluation microphone 152. The audible transfer function may define the response of the evaluation microphone 152 to the output of the speaker 104. The parameters describing the transfer function may be saved in the audible model database 314 for later use. The parameters may be communicated to the HIL system 200.

Fig. 4 depicts a flow diagram of a possible sequence of operations for implementing the HIL system 200. At operation 402, a test period may be selected. The selection may be an automated selection in which the controller sequences through a predetermined set of test cycles. In some configurations, an operator may select a test period. At operation 404, the controller may be configured to play back the noise signal from the pre-recorded data (e.g., from the vehicle data database 308). The noise signal may be output as a microphone signal to the NMM 102. At operation 406, speaker signals may be received from the NMM 102. The NMM 102 may process the microphone data and generate speaker data. At operation 408, the speaker signals may be processed by the vehicle acoustic model 224. For example, a real-time convolution may be performed on the speaker signal and one or more time-domain transfer functions of the vehicle acoustic model 224. At operation 410, the output of the vehicle acoustic model 224 may be combined with the playback noise signal to derive a microphone signal. The combined signal may represent the microphone data after the noise compensation signal has been applied. At operation 412, the combined signal may be output to the microphone interface 212.

At operation 416, the audible model 248 may be applied to the speaker signal. For example, a real-time convolution may be performed on the speaker signal and one or more time-domain transfer functions of the audible model 248. At operation 418, the output of the audible model 248 may be combined with the playback noise signal to derive a sound output signal. The combined signal may represent the estimated microphone data after the noise compensation signal has been applied. At operation 420, the combined output may be provided to the listener's headphones 234. At operation 414, the noise, compensated noise signal, and audible model output may be stored or processed for further analysis. The operations depicted are not necessarily performed sequentially and the operations may be performed in parallel. Further, the sequence of operations may be iterative, and the sequence may be repeated at predetermined intervals.

Although the HIL system 200 is described above with reference to a vehicle-based active noise management system, the use of the HIL system 200 need not be limited to an automotive environment. HIL system 200 may find use in any application in which an active noise management system may be used. The method of collecting data and replaying data in the HIL system 200 may be used to test other types of active noise management systems.

The HIL system 200 improves testing and calibration of the noise management system of the vehicle. The HIL system 200 can also reduce development costs because development can be done under laboratory conditions without the need for a vehicle for development. The HIL system 200 also allows for consistent and accurate reproduction of the vehicle noise environment, which allows for more cost-effective tuning and calibration of the noise management system.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. In addition, features of the various implemented embodiments may be combined to form further embodiments of the invention.

Claims

1. A system for evaluating a noise management module of a vehicle, the system comprising:

a controller programmed to:

receiving a speaker signal from the noise management module and transmitting a microphone signal to the noise management module;

filtering the speaker signal with a vehicle acoustic model to generate a sound signal caused by the speaker signal at a location in the vehicle corresponding to a location of a microphone associated with the noise management module;

generating a sound profile, combining the sound profile and the sound signal to generate the microphone signal;

filtering the speaker signal with an audibility model to produce a rendered sound signal, thereby creating a spatial listening impression to simulate sound caused by the speaker signal at a predetermined location within the vehicle different from the location corresponding to the location of the microphone; and is

Applying a convolution function to the time-domain transfer function via the audible model to provide a time-domain signal indicative of the sound at the user's ear,

wherein the vehicle acoustic model defines a cabin acoustic transfer function between the speaker signal and a microphone located in the vehicle and associated with the noise management module;

wherein the audible model represents an acoustic environment of the vehicle and defines a transfer function between sound caused by the speaker signal and sound at the predetermined location.

2. The system of claim 1, wherein the predetermined location is associated with a seating position within the vehicle and an expected positioning of a head of a vehicle occupant seated in the seating position.

3. The system of claim 1, wherein the audible model is derived from actual speaker data from the vehicle and actual microphone data from an evaluation microphone placed near the predetermined location in the vehicle.

4. The system of claim 1, wherein the controller is further programmed to combine the rendered sound signal with the sound profile to generate an evaluation sound signal.

5. The system of claim 4, wherein the controller is further programmed to output the evaluation sound signal to an audio output device.

6. The system of claim 1, wherein the vehicle acoustic model is derived from previously recorded speaker data from the vehicle and previously recorded data from a microphone in the vehicle associated with the noise management module.

7. The system of claim 1, wherein the sound profile comprises sound signals previously recorded in the vehicle.

8. The system of claim 1, wherein the sound profile comprises synthesized sound data.

9. The system of claim 1, wherein the controller is further programmed to transmit bus communication data and sensor signals corresponding to and synchronized with the sound profile to the noise management module.

10. A method for simulating performance of a noise management module of a vehicle and implementing in a controller, the method comprising:

filtering the speaker signal with a cabin acoustic model to generate a sound signal caused by the speaker signal at a location in the vehicle corresponding to a location of a microphone associated with the noise management module;

generating a sound profile, combining the sound profile and the sound signal to generate a microphone signal;

outputting the sound signal to a microphone input of the noise management module based on the sound profile and the cabin acoustic model, the cabin acoustic model defining a cabin acoustic transfer function between the speaker signal and a microphone located in the vehicle and associated with the noise management module;

outputting a previously recorded and synthesized sound signal in the vehicle to an audio output device based on the sound profile and an audible model defining an audible transfer function between the speaker signal and a differently positioned location within the vehicle corresponding to the microphone for rendering sound to create a spatial listening impression to recreate a sound impression at the location; and

applying a convolution function to the time-domain transfer function via the car acoustic model to provide a time-domain signal indicative of sound at the user's ear.

11. The method of claim 10, wherein the sound profile comprises sound signals previously recorded in the vehicle.

12. The method of claim 10, further comprising outputting bus data and sensor signals associated with the sound profile to the noise management module.

13. The method of claim 10, further comprising generating the audible model from actual speaker data from the vehicle and data from an evaluation microphone placed near the location.

14. The method of claim 10, wherein the position is associated with a seating position within the vehicle and an expected location of a head of a vehicle occupant seated in the seating position.

15. A non-transitory computer readable medium storing a computer program which when executed by a processor is for performing steps of simulating performance of a noise management module of a vehicle, the steps comprising:

receiving a speaker signal from the noise management module;

communicating a microphone signal to the noise management module;

outputting microphone signals via a microphone interface based on the sound profile and a cabin acoustic model, the cabin acoustic model defining a cabin acoustic transfer function between the speaker signals and a microphone located in the vehicle and associated with the noise management module;

outputting the previously recorded and synthesized sound signal in the vehicle to an audio output device based on the sound profile and an audibilization model defining an audibilization transfer function between the loudspeaker signal and a differently positioned location within the vehicle corresponding to the microphone for creating a spatial listening impression to recreate a sound impression at the location; and

applying a convolution function to the time-domain transfer function via the cabin acoustic model to provide a time-domain signal indicative of the sound at the user's ear.

16. The computer-readable medium of claim 15, further comprising instructions for exchanging data associated with the sound profile and sensor signals between a controller and the noise management module.

17. The computer readable medium of claim 15, wherein the position is associated with a seating position within the vehicle and an expected positioning of a head of a vehicle occupant seated in the seating position.

18. The computer readable medium of claim 15, wherein the cabin acoustic model is derived from actual speaker data from the vehicle and actual data from the microphone in the vehicle associated with the noise management module, and the audibility model is derived from the actual speaker data and actual microphone data from an evaluation microphone placed near the location in the vehicle.

19. The computer readable medium of claim 15, wherein the audio output device is a headset.